Diastereoselective synthesis of dihydroindolizin-3(2H)-one derivatives via catalytic sulfur-Michael addition triggered intramolecular tandem sequence

A diastereoselective synthesis of functionalized dihydroindolizidine derivatives bearing sulfur moiety was reported with high stereoselectivity via a catalytic sulfur-Michael addition triggered intramolecular aldol-type tandem sequence. This protocol allowed to readily access trans- and cis-dihydroindolizidine products in high yields with moderate to excellent diastereoselectivities under the optimized mild reaction conditions, which also can be easily transformed into various substituted functionalized pyridines incorporating β-quaternary carbon centers.